The Mesozoic Era observed the rise of several of the many iconic animals, from Tyrannosaurus rex to birds and mammals.

You are watching: Which era is known as the age of reptiles


New research says that reptiles that lived throughout the dinosaur age were hard-hit. Here, the carnivorous lizard Palaeosaniwa chases a pair the young Edmontosaurus when the line Cerberophis and the lizard Obamadon look on. (Image credit: Carl Buell)
During the Mesozoic, or \"Middle Life\" era, life diversified rapidly and also giant reptiles, dinosaurs and also other monstrous beasts roamed the Earth. The period, i beg your pardon spans from around 252 million years back to about 66 million year ago, was likewise known together the age of reptiles or the period of dinosaurs.


English geologist man Phillips, the first person to create the worldwide geologic timescale, an initial coined the ax Mesozoic in the 1800s. Phillips discovered ways come correlate sediments found around the people to particular time periods, stated Paul Olsen, a geoscientist in ~ the Lamont-Doherty earth Observatory in ~ Columbia college in new York.

The Permian-Triassic boundary, in ~ the start of the Mesozoic, is identified relative to a details section of sediment in Meishan, China, whereby a kind of extinct, eel-like creature well-known as a conodont very first appeared, according to theInternational board of directors on Stratigraphy.

The finish boundary for the Mesozoic era, theCretaceous-Paleogene boundary, is defined by a 20-inch (50 centimeters) special sliver of rock in El Kef, Tunisia, which contains well-preserved fossils and also traces of iridium and other facets from the asteroid influence that wiped out the dinosaurs. The Mesozoic era is split up right into the Triassic, Jurassic, and also Cretaceous periods.

Life and also climate

The Mesozoic era began about around the time of the end-Permian extinction, i beg your pardon wiped the end 96 percent of maritime life and 70 percent of every terrestrial types on the planet. Life gradually rebounded, eventually giving means to a thriving diversity that animals, from huge lizards come monstrous dinosaurs.

TheTriassic period, indigenous 252 million come 200 million year ago, experienced the climb of reptiles and the first dinosaurs. TheJurassic period, from around 200 million to 145 million year ago, introduced birds and mammals. And also theCretaceous period, indigenous 145 million to 66 million years back is well-known for its above dinosaurs, such asTriceratops,and pterosaurs together asPteranodon.

Coniferous plants, or those that have actually cone-bearing seeds, already existed in ~ the start of the era, but they became much more abundant during the Mesozoic. Flowering plants emerged throughout the late Cretaceous period. The lush tree life during the Mesozoic era listed plenty of food, allowing thebiggest of the dinosaurs, such together theArgentinosaurus, to flourish up come 80 tons, according to a 2005 research in the newspaper Revista del Museo Argentino de Ciencias Naturales.

Earth throughout the Mesozoic era was much warmer than today, and also the planet had actually no polar ice cream caps. During the Triassic period,Pangaeastill created one substantial supercontinent. There is no much coastline to moderate the continent\"s interior temperature, Pangaea experienced significant temperature swings and was spanned in large swaths of desert. However the region still had a belt of tropical rainforest in regions approximately the equator, stated Brendan Murphy, an planet scientist at St. Francis Xavier college in Antigonish, Canada.


The Mesozoic era to be bookended by two good extinctions, with one more smaller extinction occurring at the end of the Triassic period, Olsen said.

Around 252 million years ago, the end-Permian extinction wiped out most life on planet over about 60,000 years, follow to a February 2014 examine in the journalProceedings the the national Academy of Sciences(PNAS). At the end of the Triassic period, roughly 201 million year ago, most amphibious creatures and crocodile-like creatures that resided in the tropics to be wiped out. Around 65 million years ago, a huge asteroid blasted right into Earth and formed a gigantic crater at Chicxulub in the Yucatan Peninsula.

Because the fossil record is incomplete, it\"s difficult to say exactly what led to the extinctions, or also how promptly they occurred. After ~ all, certain types or traces that catastrophic events could be missing in the fossil record simply because the sediments may have actually disappeared over tens of millions of years, Olsen said.

\"Nature is very efficient at gaining rid of its corpses,\" Olsen told Live Science.

However, there room a few prime doubt in each of the extinctions.

At the finish of the Permian, the Siberian catch underwent substantial volcanic eruptions, which many geologists believe caused theworld\"s greatest extinction. Precisely how, however, is up because that debate.

The volcano eruptions caused a spike in carbon dioxide in the atmosphere, despite the 2014 PNAS study says that the spike was brief. The eruptions may have actually increased sea surface temperatures and led to s acidification that choked the end sea life. And also another study released in in march 2014 inPNASproposed the the eruptions released large troves of the elementnickel, which sustained a feeding frenzy through nickel-munching microbes well-known asMethanosarcina. Those microbes may have belched out vast amounts of methane, superheating the planet.

Most scientists agree that anasteroid influence wiped the end the dinosaursat the end of the Cretaceous period. The affect would have kicked up so lot dust that it blocked the sun, stopped photosynthesis, and also led to together a huge disruption in the food chain that whatever that wasn\"t a scavenger or very tiny died.

But theDeccan Traps, in what is currently India, to be spewing massive quantities of lava both before and after the asteroid impact, and also a few scientists think these operation either directly caused or sped up the dinosaurs\" demise.

Volcanism may additionally be come blame because that the end-Triassic extinction. Despite volcanism in basic leads to global warming, ~ an initial volcanic eruption, vast amounts of sulfur spew right into the air and cause a brief duration of global cooling. Together cooling-heating cycles might have developed hundreds that times over 500,000 years. Similar cold snaps have actually been tied to vast crop fail in historical times, such together in Iceland in the 1700s, Olsen said.

As a result, animals used come constant, balmy temperatures in the tropics to be wiped out, while pets that were insulated with proto-feathers, such as pterosaurs, or that lived at higher latitudes and were already adapted to big temperature variations, did just fine, Olsen said.

See more: Change Transmission Fluid 2001 Toyota Camry Transmission Fluid Capacity

\"When you have actually these volcano winters, whereby temperatures may have dropped even below freezing in the tropics, it was devastating,\" Olsen said.